Certain embodiments of the present invention relate generally to testing optical networking hardware, and more particularly to a system and method for performing standalone self-testing.
High-speed digital communication networks over copper and optical fiber are used in many network communication and digital storage applications. Ethernet and Fiber Channel are two widely used communication protocols used today and continue to evolve to respond to the increasing need for higher bandwidth in digital communication systems.
The Open Systems Interconnection (OSI) model (ISO standard) was developed to establish standardization for linking heterogeneous computer and communication systems. The OSI model includes seven distinct functional layers including Layer 7: an application layer; Layer 6: a presentation layer; Layer 5: a session layer; Layer 4: a transport layer; Layer 3: a network layer; Layer 2: a data link layer; and Layer 1: a physical layer. Each OSI layer is responsible for establishing what is to be done at that layer of the network but not how to implement it.
Layers 1 to 4 handle network control and data transmission and reception. Layers 5 to 7 handle application issues. Specific functions of each layer may vary to a certain extent, depending on the exact requirements of a given protocol to be implemented for the layer. For example, the Ethernet protocol provides collision detection and carrier sensing in the data link layer.
The physical layer, Layer 1, is responsible for handling all electrical, optical, and mechanical requirements for interfacing to the communication media. The physical layer provides encoding and decoding, synchronization, clock data recovery, and transmission and reception of bit streams. Typically, high-speed electrical or optical transceivers are the hardware elements used to implement this layer.
As data rate and bandwidth requirements increase, 10 Gigabit data transmission rates are being developed and implemented in high-speed networks. Pressure exists to develop a 10 Gigabit physical layer for high-speed serial data applications. Transceivers for 10 G applications are needed for the 10 G physical layer. The specification IEEE P802.3ae draft 5 describes the physical layer requirements for 10 Gigabit applications and is incorporated herein by reference in its entirety.
An optical-based transceiver, for example, includes various functional components such as clock data recovery, clock multiplication, serialization/de-serialization, encoding/decoding, electrical/optical conversion, descrambling, media access control, controlling, and data storage. Many of the functional components are often implemented each in a separate IC chip.
Testing of IC chips often involves applying inputs and capturing outputs by an external source. The external source then compares the captured outputs against expected outputs that are known to be accurate. Defective IC chips are detected when the captured outputs are inconsistent with the expected outputs.
Testing an IC chip by application of inputs and capturing of outputs by an external source becomes difficult as the data rate of the IC chip increases. The external source must apply the inputs and capture the outputs at the data rate of the IC chip. As stated above, IC chips in optical transceivers may be required to operate with data at rates of 10 Gbps.
Further limitations and disadvantages of conventional and traditional approaches will become apparent to one of skill in the art, through comparison of such systems with the present invention as set forth in the remainder of the present application with reference to the drawings.